[rchalwin]

Hi All, I'm having a problem accessing the secure FTP (explicit TLS) server on a Thecus N4800 remotely.

The process on the N4800:
Enabled FTP and secure FTP
Set port 21
Set external IP to my WAN public IP
Passive port 30000-32000
Char set: UTF-8
No anon access

Connecting when in this config on LAN works so I know the FTP server works

I then set the router to forward ports 20, 21 and 30000-32000 to N4800's LAN ip

Connecting remotely with FlashFXP (4.2.5) using settings:
FTP explicit TLSv1
domain registered with no-ip.org DDNS entered and correctly pointing
port 21
PASV

yields the following and won't connect:
[R] Connecting to Remote Home FTP -> DNS=xxxxxxxxx.no-ip.org IP=xxx.xxx.xxx.xxx PORT=21
[R] Connected to Remote Home FTP
[R] 220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
[R] 220-You are user number 1 of 300 allowed.
[R] 220-Local time is now 21:12. Server port: 21.
[R] 220-This is a private system - No anonymous login
[R] 220-IPv6 connections are also welcome on this server.
[R] 220 You will be disconnected after 15 minutes of inactivity.
[R] AUTH TLS
[R] 234 AUTH TLS OK.
[R] Connected. Negotiating SSL/TLS session
[R] Failed SSL/TLS negotiation, disconnected
[R] Connection failed (Connection closed by server)

It made no difference setting PORT(Active) instead of PASV

Nor did putting the N4800 in DMZ.

Both unsecured FTP and SFTP-over-SSH connect remotely with no errors so I'm at a loss to explain why FTPS in particular is playing up.

P.S: I've lodged a similar query on the Thecus forum too